Yahoo CEO Jerry Yang said Monday that the struggling Sunnyvale Internet giant still has the “same old face,” but that it has a better sense of how to keep Yahoo indispensable for its users as the Web continues to evolve.

“I think it’s time to get Yahoo yodeling again,” Yang said at a speech at the Consumer Electronics Show in Las Vegas.

Yang offered a peek into how it would like to update and integrate its e-mail services, such as using a person’s social networks and how frequently the person is in contact with a friend to determine the e-mails the person is most likely going to want to read first.

Yahoo also announced Monday it is opening up its online mobile technology, allowing outside developers such as eBay and MySpace to create widgets that can be distributed through Yahoo’s mobile services.

Yahoo said it hopes to make it easier for outside developers to create programs for cell phones, which could lead to more consumers using the Internet and Internet services on their phones.

Right now, it’s a challenge for developers because of the massive number of cell phones types and carriers.

Yahoo’s approach comes as rival Google develops Android, its mobile operating system, and Apple offers a software developer kit for developers who want to create programs for the iPhone. But Yahoo said that it believes its approach could be more appealing for developers, since they could use Yahoo to reach across multiple cell phones, mobile operating systems including Android, and carriers.

Yahoo will also allow developers to sell their own advertising on their programs. For instance, MTV, one of Yahoo’s mobile partners, said it plans to sell ads that will run on its MTV News widget, alongside updated news of Britney Spears and others, said Greg Clayman, MTV’s executive vice president of digital distribution and business development.